Introduction: Patients with insulin-treated diabetes mellitus need to self-test their blood glucose several times a day. This study was undertaken to evaluate the meal-related performance of TensorTip CoG, a non-invasive glucose monitoring device (NI-CoG), with an additional built-in invasive glucose meter (Inv-CoG) in different patient populations during a standardised meal experiment. Methods: The study cohort comprised 15 healthy volunteers (HV), 6 patients with type 1 diabetes (T1D), and 15 with type 2 diabetes (T2D). Participants took a standardised meal. Glucose was assessed by means of NI-CoG, and from capillary blood samples by means of Inv-CoG,YSI Stat 2300 plus, and Ascensia Contour Next at time-points -30, 0, 15, 30, 45, 60, 75, 90, 120, 150, and 180min. Results: Similar results were obtained from each individual device in all three study cohorts. MARD results for values > 100 mg/dl using NI-CoG were determined at 11.1 % (HV), 13.2 % (T1D), and 13.6 % (T2D) (NICoG MAD for values <= 100 mg/dl: 20.0 mg/di, 18.8 mg/dl, 20.0 mg/dl. Inv-Cog: MARD: 8.9%, 76%, 8.0%, and MAD: 11.5 mg/dl, 13.4 mg/di, 14.2 mg/dL. Contour: MARD: 4.4%, 4.1 %, 3.9 %, and MAD: 4.3 mg/dl, 2.6 mg/dl, 4.9 mg/dl). All data pairs appeared in CGA zones A and B using all devices (NI-CoG: 83% and 17%, Inv-CoG: 100% and 0%, Contour: 100% and 0%). Conclusion: According to this study, NI-CoG technology reliably tracked meal-related glucose excursions in all three patient populations with similarly acceptable performance compared to common needle sensor methods.